Ghanbari, R. Bate, C. Deyu, G.K. Hillert, W. Monroy-Villa, R. Reschke, D. Steder, L. Wenskat, M. Wolff, J.C. JACoW Publishing Geneva, Switzerland 2673-5504 978-3-95450-234-9 10.18429/JACoW-SRF2023-MOPMB021 English 124-128 Contribution to a conference proceedings 2023 2023-09 https://doi.org/10.18429/JACoW-SRF2023-MOPMB021 https://jacow.org/srf2023/papers/mopmb021.pdf Heat treatment procedures have been identified as cru-cial for the performance of niobium SRF cavities, which are the key technology of modern accelerators. The so called "mid-T heat treatments", invert the dependence of losses on the applied accelerating field (anti-Q slope) and significantly reduce the absolute value of losses. The mechanism behind these improvements is still under investigation, and further research is needed to fully understand the principle processes involved. Anomalies in the frequency shift near the transition temperature (Tc), known as "dip" can provide insight into fundamental material properties and allow us to study the relation-ship of frequency response with surface treatments. Therefore, we have measured the frequency versus temperature of multiple mid-T heat treated cavities with different recipes and studied the correlation of SRF properties with frequency shift features. The maximum quality factor correlates with two such shift features, namely the dip magnitude per temperature width and the total frequency shift.